/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package cn.cloud.all.security.core.http;

import org.springframework.http.converter.GenericHttpMessageConverter;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.GsonHttpMessageConverter;
import org.springframework.http.converter.json.JsonbHttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.util.ClassUtils;

final class HttpMessageConverters {
    private static final boolean jackson2Present;
    private static final boolean gsonPresent;
    private static final boolean jsonbPresent;

    static {
        ClassLoader classLoader = HttpMessageConverters.class.getClassLoader();
        jackson2Present = ClassUtils.isPresent("com.fasterxml.jackson.databind.ObjectMapper", classLoader) && ClassUtils.isPresent("com.fasterxml.jackson.core.JsonGenerator", classLoader);
        gsonPresent = ClassUtils.isPresent("com.google.gson.Gson", classLoader);
        jsonbPresent = ClassUtils.isPresent("javax.json.bind.Jsonb", classLoader);
    }

    static GenericHttpMessageConverter<Object> getJsonMessageConverter() {
        if (jackson2Present) {
            return new MappingJackson2HttpMessageConverter();
        } else if (gsonPresent) {
            return new GsonHttpMessageConverter();
        } else if (jsonbPresent) {
            return new JsonbHttpMessageConverter();
        }
        return null;
    }
}
